This VCO with discrete components was found documentation from the 1980s. The central frequency with the indicated components is 8 kHz. A BC548 can be used for Q1.
This 6V regulator with FET was found in an old Electronic Design. FET and transistor admit modern...
Frequency Indicator (CB6342E) This simple circuit was found in an Exar publication from the 1970s....
The circuit shown in the figure differs from the previous one (CIR8909) in that it can be...